Apparatus for heat-treating travelling threadlike products



May 6, 1969 3,441,993

APPARATUS FOR HEATTREATING TRAVELLING THREADLIKE PRODUCTS Filed May 29, 1967 w. STELWAGEN Sheet INVENTOR Willem Sieimyem May 1, I v W. STELWAGEN-' 3, 1,

APPARATUS FOR HEAT-TREATING TRAVELLING THREADLI'KE PRODUCTS Filed May 29, 1967 Sheet 2 or s INVENT OR PVzZ/ezzz Si h aye May (-3, 1969 w. STELWAGEN APPARATUS FOR HEAT-TREATING TRAVELLING THREADLIKE'PRODUCTS R 3 m r 7 M a Cu S m United States Patent US. Cl. 28-62 25 Claims ABSTRACT OF THE DISCLOSURE An apparatus for uniformly heat-treating travelling synthetic yarns or other threadlike products which comprises a plurality of processing positions or units for the yarn, each unit comprising yarn feeding means, yarn guiding and transport means and a hollow heating element in contact with the yarn, a main supply line extending along the processing units for conveying a heated, condensing vapor, e.g., saturated steam, to the heating elements, each of the heating elements having inlet and outlet means connected to the supply line for passing heated vapor therethrough, and constriction means arranged in the supply line for providing a reduced flow passage within a portion of the supply line adjacent to each heating element and operatively associated with the inlet and outlet means of each heating element to ensure substantially uniform vapor su ply, vapor discharge and condensate discharge for all heating elements.

This invention relates to an apparatus for heat-treating a travelling synthetic yarn, thread or the like thread like product and more particularly to an apparatus, e.g., a drawtwisting machine, having a plurality of processing positions or units for the yarn, each unit including a hollow heating element, such as a hot pin, plate, tube or roll, which is in contact with the yarn and which is heated by a condensing gas or vapor, e.g., saturate-d steam, and having means to ensure uniform heating of the yarn by all the heating elements.

Apparatus having a plurality of processing units for treating yarn which are similar to the apparatus described herein are known. The known drawtwisting machines also serve to hot-draw and subsequently twist and wind yarns, more particularly polyamide or polyester yarns. In general, such drawtwisting machines comprise an elongated frame with, for instance, about 70 processing units or positions for the yarn on either side.

The known apparatus have the disadvantage that when a large number of heating elements are used per machine, the deaeration, the heating of the yarn (particularly the uniformity), the steam supply, and the steam and condensate discharge are not quite satisfactory or at least not such that the necessary high demands can be satisfied. It is particularly difiicult with the known apparatus to have the heating of the yarn on the heating element proceed satisfactorily at high yarn speeds. Advantageously this invention provides an apparatus for heating yarn which no longer shows the aforementioned disadvantages.

Thus, this invention contemplates an apparatus for uniformly heat-treating a travelling synthetic yarn or other threadlike product which comprises a frame with a plurality of processing positions or units for the yarn,

3,441,993 Patented May 6, 1969 'ice each unit comprising yarn feeding means, yarn guiding and transport means and a hollow heating element in contact with the yarn, a main supply line extending along the processing units for conveying a heated, condensing vapor to the heating elements, each of the heating elements having inlet and outlet means connected to the supply line for passing the heated vapor therethrough, and constriction means arranged in the supply line for providing a reduced flow passage within a portion of the supply line adjacent to each heating element and operatively associated with the inlet and outlet means of each heating element to ensure substantially uniform vapor supply, vapor discharge and condensate discharge for all heating elements.

More particularly, the constriction means of the apparatus provide a locally reduced flow passage in the main supply line adjacent to each heating element that is at least 20% smaller than that of the adjoining portion of the supply line and the inlet means of each heating element is connected to the supply line substantially upstream of the reduced flow passage and the outlet means is connected to the supply line substantially at or downstream of the reduced flow passage.

The apparatus according to the invention is further characterized in that the cross-sectional area of each of the reduced flow passages provided in the supply line is preferably 50 to smaller than of the adjoining line portions.

Advantageously, the apparatus of the invention may be so constructed that each constriction means for providing a reduced flow passage in the supply line is formed by a tubular member which, in the direction of the fluid flow, successively converges and diverges, and the outlet means leading from the hollow space or portion of the heating element is connected to the supply line substantially at the point of the smallest cross-sectional area of the reduced flow passage.

Another embodiment for the apparatus of this invention is characterized in that each constriction means in the flow passage of the supply line is formed by a recess in the lower part of a transverse partition placed in the supply line.

The apparatus according to the invention is further characterized in that the reduced flow passage provided by the constriction means located near one heating element is larger than the reduced flow passage provided by the constriction means in the supply line near another heating element positioned downstream thereof.

These and other characteristics of the apparatus according to the invention make it possible to obtain a relatively great difference in pressure between the inlet and outlet means connected to the hollow portion or space of each heating element, the latter of which debouch to the supply line extending along the apparatus. The construction according to the invention provides a heating system that ensures a uniform steam supply, steam discharge and condensate discharge for all heating elements. Moreover, the heating elements are flushed with steam so that all non-condensing gases, particularly air, are automatically forced from the heating elements to a collecting element. From the collecting element at the end of the system the non-condensing gases can periodically be removed, for instance with the aid of automatic deaerators (which are in themselves known). The substantially complete removal of the non-condensing gases from the system and a thorough discharge or condensate from each of the heating elements are necessary in order to obtain a uniform temperature and a maximum heat transfer to the entire surface of each of the heating elements and to prevent the heating elements from having different temperatures. These measures lead to a high quality and uniformity of the treated yarns, so that they fully satisfy the demands made thereon.

The apparatus according to the invention is relatively cheap to construct in practice if for a group of, e.g., twelve successive heating elements, the reduced flow passages in the supply line near these heating elements are of the same magnitude, and the reduced flow passages in the supply line near the next group of heating elements in the direction of flow are smaller. In other words, the cross-sectional areas of the flow passages near the heating elements will decrease group-wise in the direction of flow.

The hollow portion of each heating element must be so constructed that the heating elements can be effectively flushed to remove the non-condensing gases. The hollow portion in each of the heating elements may, for instance,

be formed by a U-shaped channel, through one leg of which steam is fed from the supply line and through the other leg of which steam flows back from the heating element to the supply line extending along the apparatus.

With the apparatus according to the invention the hollow portion in the heating element, advantageously, may be partially divided into two spaces by a partition which forms a continuation of the transverse partition that provides a local reduction in the flow passage of the supply line. The partition in the hollow portion of the heating element may be positioned in the same plane as the aforementioned transverse partition. A simple embodiment is obtained when the partition in the hollow portion of the heating element is plate-shaped and is integrally formed with the partition forming the local constriction or reduction in the flow passage of the supply line.

Furthermore, it has been found that a particularly simple and efficacious construction for an apparatus of the above type is obtained when the transverse partition is detachably provided in the main supply line and the width of at least that part extending into the main supply line is substantially equal to the diameter of the main supply line. In this way, the simple, inexpensive transverse partitions can readily be replaced by transverse partitions having larger or smaller flow openings, which may be necessary in the case of a change in the load applied to the heating elements.

Changes in the loading of the heating elements may be required, for instance, when a different type of yarn, a yarn having a different denier or a yarn travelling at a different speed must be heated.

According to one embodiment of the apparatus of this invention, each heating element is connected to the main supply line by a connecting piece or member. In this embodiment of the invention the transverse partition for providing reduced flow passage may be placed in the correct angular position in the main supply line if the connecting piece and the transverse partition are provided with intercooperating means consisting of a projection which preferably forms part of said partition and which fits in a recess provided in the connecting piece.

A preferred embodiment of the apparatus is characterized in that at the end remote from the main supply line, the transverse partition is axially retained in the hollow space inside the heating element or in the collar of a flange attached to the heating element.

When the heating element is formed by a pin, then the apparatus according to the invention is, advantageously, characterized in that the heating element is attached to the connecting piece by a number of bolts or screws which axially extend entirely or partly through the pin.

According to the invention the connecting piece may be a section of thick-walled piping.

When the heating element is formed by a hot plate which contains a substantially U-shaped channel, one leg of which forms part of the inlet means and the other a part of the outlet means, then the apparatus according to the invention is advantageously characterized in that the portion of the transverse partition outside the main supply line is deflected in two directions for the purpose of connecting the two free ends of the U-shaped channel, respectively, to opposite sides of the transverse partition in the supply line.

The invention will be further described with reference to the accompanying schematic drawings; in which FIGURE 1 is a schematic representation of an embodiment of the apparatus of this invention for hot drawing of yarn by use of a plurality of hot plates;

FIGURE 2 shows a cross-section of one embodiment of a hot plate and a connection of the hot plate to a steam supply line;

FIGURE 3 is a partial side elevation of the embodiment shown in FIGURE 2;

FIGURE 4 shows another embodiment of a connection of the hot plate to a steam supply line;

FIGURE 5 is a side elevation of the embodiment shown in FIGURE 4;

FIGURE 6 shows a schematic arrangement of and the connection of a plurality of hot pins on the apparatus of the invention for the hot drawing of yarn;

FIGURE 7 shows, on an enlarged scale, a perspective view of an embodiment of one hot pin and a connection of the pin to a steam supply line; and

FIGURES 8 and 9 show, on an enlarged scale, perspective views of two other embodiments of the construction of and the connections of heating elements to a steam supply line.

FIGURE 1 is a schematic representation of a drawtwisting machine with a plurality of processing positions or units on either side of the machine. As is shown in FIGURE 1, each processing position comprises a yarn package 1 from which the yarn 2 is drawn off overhead by a driven feed roller 3 with presser roller 4. Then the yarn is guided over the hot plate 5 to be heated to the desired temperature, which in the case of polyamide yarn may be approximately 180 C. After leaving the hot plate the yarn 2 travels to a draw roller 6 with an idler 7, which is driven at a speed that is a few times higher than that of the feed roller. Consequently the yarn is drawn between the rollers. Subsequently, the yarn 2 is, via an eyelet 8 and a twisting ring 9 having a revolving traveller that traverses in the direction indicated by the arrow, wound into a package 11 on a bobbin 10.

The bobbin 10 is positioned on a twisting spindle (not shown) which is rotatably mounted in the framework of the machine. It will be understood that the various other parts, such as the feed roller and the presser roller and the draw roller and idler, et cetera, also are suitably mounted in the framework of the machine. Since the present invention particularly relates to the construction and connection of the heating elements to the supply line, only the hot plates 5 at the other processing positions in FIGURE 1 are shown. The processing positions as such are indicated by vertical center lines 12.

A steam supply line 13 extends along the successive hot plates 5. Line 13 starts from and ends in a controller 14 placed at the head of the machine, in which controller there are provided a steam source and a controlling and regulating system (not shown) which is in itself known. The steam and the condensate subsequently formed flow through the supply line 13 in the direction indicated by the arrow 15. Spaced some distance apart are condensate lines 16. These lines are connected to the lower side of the supply line 13 and serve to discharge the condensate downwards to the main condensate line 17 in which the condensate flows back to the controller 1'4 in the direction indicated by the arrow 18.

As shown in FIGURE 2 the hollow portion or the heating space within each hot plate 5 has an inlet 19 and an outlet 20 connected to the steam supply line 13. The

heating space in this embdoiment of the plate is formed by the U-shaped channel 21. Near each position at which a hot plate is connected to the steam supply line 13, the cross-sectional area of its flow passage is preferably 50 to 95 percent smaller than in the adjoining line portions.

As shown in FIGURES 2 and 3 the locally reduced flow passage near each hot plate in the supply line 13 is provided by positioning a constriction means in the form of a transverse partition 22 within the supply line. This partition has a V-shaped recess 23 at its lower side. The inlet 19 to the hollow portion in a hot plate 5- is positioned upstream of the reduced flow passage provided by the transverse partition 22, whereas the outlet 20 of the hot plate debouches into the supply line 13 downstream of the partition 22.

The local reduction of the flow passage in line 13 results in a fiow pattern which is approximately shown by the line 24. This flow pattern leads to a local drop in pres sure downstream of the partition. As a result, steam enters the hot plate 5 in the direction indicated by the arrow 25 and leaves the hot plate in the direction indicated by the arrow 26. The difference in pressure primarily causes the hot plate to be properly flushed with steam, which in its turn effects satisfactory deaeration and'heating. Secondarily, the steam is caused to exert an effective pumping action on the condensate on the bottom of the steam supply line 13.

FIGURES 4 and 5 show an alternative connection between the hotplate 5 and the steam supply line 13, in which each reduced fiorw passage in the supply line 13 is formed by a tubular member or constriction which successively converges and diverges in the direction of flow. The inlet 19 of the hot plate 5 is positioned upstream of the member 27. The outlet 20 of the hot plate connects with the narrowest passage within the member 27. On the lower side of the tubular member 27 there is provided an axial channel 28 for permitting the passage of the formed condensate. The tubular member 27 also causes a difference in pressure between the steam entering and leaving the hot plate, and the resulting flow pattern of the steam is approximated by the lines 29.

FIGURE 6 schematically shows an arrangement of a large number of hot pins 30 in an apparatus for the hot drawing of yarn. Also in this case only the connections between the heating elements and the supply line are shown, because the other parts of the drawing apparatus are known and the remaining elements are similar to those shown in FIGURE 1. As illustrated, each of the hot pins are connected to a supply line 13 by a single connecting piece or member.

In the supply line 13 there are again positioned transverse partitions 22 provided with V-shaped recesses 23 (see FIGURES 3 and 7). The recesses need not be V- shaped but may, for instance, be circular. With a line 13 having an inner diameter of 34 mm. it has been found that a proper heating and flushing of the hot pins 30 is obtained if the height 31 (that is the radial distance between the apex of the recess and the wall of the supply line) of each of the V-shaped recesses for twelve successive pins has, in the direction of flow of the stream, the following successive values: 10.5 mm, 10.3 mm., mm., 9.5 mm, 9 mm., 8.7 mm, 8.3 mm., 7.5 mm., 7 mm., 6.5 mm., and 6 mm.

FIGURE 7 shows in perspective another embodiment of a connection of a hot pin 30 to the steam supply line 13. The hot pin 30, over the outer surface of'vwhich the yarn to be heated is passed, comprises a hollow heating space 32 which is partially divided into two flow paths by a plate-shaped partition 33. The partition 33 continues outside the pin 30 into the tubular connecting piece 34 and is formed integral with the transverse partition 22 in the steam supply line. The transverse partition also is provided with a V-shaped recess 23. As illustrated in this embodiment the connecting piece 34 is in communication with the supply line and the hollow space 32 of the pin.

FIGURES 8 and 9 show that the locally reduced flow passage near each heating element may be obtained by providing a transverse partition 39' which is provided at its base with a circular flow opening 40. At its lower side the circular opening is interrupted by a small approximately rectangular recess 41 which provides a passage for condensation water collected on the bottom of the main line 13. The local reduction in the flow passage results in a locally increased rate of flow of the steam in the line 13. This, in turn, leads to a local drop in pressure downstream of the partition. As a result, steam upstream of the partition 39 flows to the hot pin 44 or the hot plate 45 in the direction indicated by the arrows 42 and 43, respectively, shown in the FIGURES 8 and 9. Downstream of the partition 39, after partial condensation, the steam flows back into the main supply line in the direction indicated by the arrows 46 and 47, respectively.

Near each heating element a connecting piece or member 48 is mounted on the main line 13. The outside of the connecting piece is shown block-shaped in the drawings but it also may be cylindrical. The cylindrical space in the connecting piece 48 is divided into two halves by the partition 39, namely a feed and a discharge half, The portion of then partition 39 extending into the main supply line 13 has a Width 49 which is practically equal to the inner diameter 50 of the main line 13. Each transverse partition 39 is provided with a lip 51 which fits in a groove 52 in the connecting piece. As a result of this arrangement the correct position of the partition 39 in the main supply line is ensured.

In order to clearly illustrate the construction of these embodiments of the connection of the heating elements to the supply line, i.e., the individual heating assembly provided at each processing unit, the hot pin 44 (FIGURE 8) and the hot plate 45 (FIGURE 9) are shown displaced in the axial direction relative to the connecting piece 48. The hot pin 44 may be directly attached to connecting piece 48 with four screws 53 which may be screwed through bores 54 in the pin 44 into corresponding screwthreaded holes 55. In order to obtain a proper sealing, a packing ring 56 is provided between the pin 44 and the connecting piece 48. In the normal assembled position the partition 39 is axially retained in the space 57 inside the pin 44. At the blind end of the space 57 the steam can pass around the edge of the transverse partition from the feed side to the discharge side thereof, as is schematically indicated by the arrow 58.

The connection of the hot plate 45, illustrated in FIG- URE 9, is effected essentially in the same Way as the connection of the hot pin shown in FIGURE 8. Attached to the lower end of the hot plate 45 is a flange 59 which is similarly secured to the connecting piece 48 with screws 53 and packing ring 56. In the hot plate 45 the steam may flow successively through the channels 60, 61, 62, 63 and 64, the channels 61, 62, 63 together forming a substantially U-shaped flow passage. At its free end the portion of the transverse partition positioned out side the main supply line is deflected in two directions, so that the lips 65 and 66 are formed, for connecting the two free ends of the legs 61 and 63 of the U-shaped channel to the appropriate spaces in the main supply line on either side of the transverse partition 39.

It should be appreciated that by the hollow portion in the heating element, also a substantially U-shaped channel is meant. Also, the vapor distribution system must, in the usual manner, he provided with a suitable thermal insulation. Furthermore, it will be recognized that although the apparatus according to the invention particularly relates to drawtwisting machines, application to other yarn processing machines, for instance box crimping machines, is also possible.

While the novel features of the invention have been shown and described and are pointed out in the appended claims, it is to be understood that various omissions, substitutions and changes in construction and arrangement 7 of the features shown and described may be made by those skilled in the art without departing from the spirit and scope of the invention.

What is claimed is:

1. An apparatus for uniformly heat-treating a traveling synthetic yarn which comprises a plurality of processing units for the yarn, each unit comprising yarn feeding means, yarn guiding and transport means and a hollow heating element in contact with the yarn, a main supply line extending along the processing units for conveying a heated, condensing vapor to the heating elements, each of the heating elements having inlet and outlet means connected to the supply line for passing heated vapor therethrough, and constriction means arranged in the supply line for providing a reduced flow passage within a portion of the supply line adjacent to each heating element and operatively associated with the inlet and outlet means of each heating element to ensure substantially uniform vapor supply, vapor discharge and condensate discharge for all heating elements.

2. The apparatus of claim 1, in which the cross-sectional area of each reduced flow passage in the supply line is locally at least 20% smaller than that of the adjoining line portion, and the inlet means of each heating element is connected with the supply line practically upstream of said reduced flow passage, and the outlet means is connected with the supply line practically at or downstream of said reduced flow passage.

3. The apparatus of claim 2, in which the cross-sectional area of each reduced flow passage in the supply line is locally approximately 50 to 95% smaller than that in the adjoining line portions.

4. The apparatus of claim 1, in which the constriction means adjacent to each heating element is formed by a tubular member which successively converges and diverges in the directon of the vapor flow.

5. The apparatus of claim 4, in which the outlet means of each heating element is connected to the supply line substantially at the point of the smallest cross-sectional area of the reduced flow passage.

6. The apparatus of claim 1, in which the constriction means adjacent to each heating element is formed by a recess in the lower part of a transverse partition placed in said supply line.

7. The apparatus of claim 1, in which the constriction means adjacent to each heating element is provided with an axial channel which extends along the lowest portion of the inner wall of the supply line for the passage Of the formed condensate.

8. The apparatus of claim 1, in which the smallest reduced flow passage located near one heating element is larger than the smallest reduced flow passage near another heating element positioned downstream thereof.

9. The apparatus of claim 1, in which the smallest reduced flow passages near a group of successive heating elments are of the same magnitude, and the smallest reduced flow passages near the next group of successive heating elements in the direction of flow are smaller.

10. The apparatus of claim 1, in which the constriction means adjacent to each heating element comprises a transverse partition having said reduced flow passage formed therein and the hollow portion of each heating element is partially divided into two spaces by a partition which forms a continuation of the transverse partition in the supply line.

11. The apparatus of claim 10, in which the partition in the hollow portion of the heating element is positioned in the same plane as the transverse partition.

12. The apparatus of claim 11, in which the partition in the hollow portion of the heating element is formed integrally with the transverse partition forming the local reduction in the flow passage.

13. The apparatus of claim 12, in which the partition in the hollow portion of the heating element is substantially plate-shaped.

14. The apparatus of claim 1, in which said heating elements are connected to the main supply line by connecting members located adjacent to the locally reduced flow passages provided by the constriction means in said main line, said constriction means being formed by recesses in transverse partitions placed in the main supply line, said partitions extending into the connecting members and separating the supply of the heating vapor to and the discharge thereof from the respective inlet and outlet means of the heating elements, each of said transverse partitions being detachably secured within the main supply line and having a portion thereof extending into the main supply line with a width substantially equal to the diameter of the main supply line.

15. The apparatus of claim 14, in which each connecting member and associated transverse partition are provided with cooperating means for correctly positioning the transverse partition in the main supply line.

16. The appartus of claim 15, in which said cooperating means comprise a projection which forms part of the transverse partition and which fits in a recess within said connecting member.

17. The apparatus of claim 14, in which at the end remote from the main supply line each transverse partition is axially retained in the hollow portion of a heating element.

18. The apparatus of claim 14, in which at the end remote from the main supply line each transeverse partition is axially retained in the collar of a flange attached to a heating element.

19. The aparatus of claim 14, in which each heating element comprises a pin attached to the connecting member by fastening means which axially extend through said pin.

20. The apparatus of claim 14, in which the connecting member is in the form of a section of thick-walled piping.

21. The apparatus of claim 14, in which the heating element is formed by a hot plate which has a substantially U-shaped channel, one leg of which forms the inlet means and the other the outlet means of the heating element, the free end of the portion of the transverse partition outside the main supply line being deflected in two directions to connect the two free ends of the U-shaped channel to the respective spaces in the main supply line on either side of the transverse partition.

22. A heating assembly for heat treating yarn in a yarn processing apparatus, comprising a hollow heating element adapted to contact and thereby heat the yarn, a supply line for conveying a heated condensing vapor, a transverse partition placed in said supply line and having a recess that forms a locally reduced flow passage within said supply line, the hollow heating member being connected to said supply line by a connecting member positioned adajcent to the locally reduced flow passage, said transverse partition having one portion extending into the connecting member and separating the supply of the heating vapor to and the discharge thereof from the hollow heating element and having another portion extending into the supply line with a width substantially equal to the diameter of the supply line.

23. The heating assembly of claim 22, in which said transverse partition is detachably secured within the supply line, and said connecting member and said transverse partition being (provided with cooperating means for correctly positioning the transverse partition in the supply line.

24. The heating assembly of claim 23, in which said cooperating means comprise a projection which forms part of the transverse partition and which fits in a recess within said connecting member 25. The heating assembly of claim 22, in which said hollow heating element is a hot plate which has a substantially U-shaped channel fromed therein, one leg of said channel forming a supply conduit and the other forming a discharge conduit, the free end of the portion References Cited UNITED STATES PATENTS 2,211,141 8/1940 Lobasso 28-62 2,820,280 1/ 1958 Benn 28-62 2,874,410 2/ 1959 Kinney.

10 Gilchrist et a1. 28-62 Gonsalves et a1. 28-61XR Coggeshall 57-555 Kodaira 28-62 XR Aelion et a1 28-62 XR JOHN PETRAKES, Primary Examiner.

US. Cl. X.R. 

